[en] High temperature magnet pump development(5 hp, 550 .deg. C, 20 kg/cm₂G); Maintainment below 60 .deg. C for magnet coupling with heat removal system, Test of magnet pump for long period under 500∼550 .deg. C in high temperature testing loop, Starting products to be commercialized the magnet pump, verifying test with performance testing of the products. High pressure magnet pump development(10 hp, 100 kg/cm₂); design of pressured case, manufacturing and testing of starting products to be commercialized the high pressure magnet pump with the performance. design of high temperature magnet coupling under 550 .deg. C, designing the magnet pump to acquire the torque of magnet coupling to be used the motor of pump, to be acquired its capacity of magnet pump, used with disc magnet and one layer followed the circle, preparation to test the magnet pumps for long period in high pressure and high temperature test loops

[en] The successful detection of a water/steam into a sodium leak in the LMR SG (steam generator) at an early phase of a leak origin depends on the fast response and sensitivity of a leak detection system. It is considered, that the acoustic system is intended for a fast detecting of a water/steam into a sodium leak of an intermediate flow rate, 1 ∼ 10 g/s, during several seconds. This intention of an acoustic leak detection system is stipulated by a key impossibility of a fast detecting of an intermediate leak by the present nominal systems such as the hydrogen meter. Subject of this study is to introduce the detection performance of the acoustic leak detection system discriminated by a back-propagation neural network with a preprocessing of the FFT power spectrum analysis and the Octave band analysis, and to introduce the status of the development of the acoustic leak detection in KAERI. It was used with the acoustic signals from the injected Argon gas into water experiments in KAERI, the acoustic signals injected from the water into the sodium obtained in IPPE, and the background noise of the PFR superheater

[en] The protection of a water/steam leak into a sodium in the SFR SG at an early phase of a leak origin depends on a fast response and sensitivity of a leak detection system not to a response against the several kinds of noises. The subject in this study is to introduce a detection performance by using our developed acoustic leak detection methodology discriminated by a backpropagation neural network according to a preprocessing of the 1/6 Octave band analysis or 1/12 Octave band analysis and the xⁿ method defined by us. It was used for the acoustic signals generated from the simulation works which are the noises of an artificial background such as a scratching, a hammering on a steel structure and so on. In a previous study, we showed that the performance of a LabVIEW tool embedded with the developed acoustic leak detection methodology detected the SWR leak signals

[en] The successful protection of a water/steam into a sodium leak in the LMR SG at an early phase of a leak origin depends on the fast response and sensitivity of a leak detection system. The control time for the protection of the LMR SG is several seconds. Subject of this study is to introduce the detection performance of the acoustic leak detection system discriminated by a back-propagation neural network according to a preprocessing of the FFT power spectrum analysis and the Octave band analysis, and to introduce the status of the development of the acoustic leak detection at KAERI. It was used for the acoustic signals from the injected Argon gas into water experiments at KAERI, the acoustic signals injected from the water into the sodium obtained in IPPE, and the background noise of the PFR superheater

[en] One of the important problems to be solved in the design and construction of a sodium cooled fast reactor is to confirm the safety and reliability of the steam generator which transfers the heat from the sodium to the water. Sodium-water reaction events may occur when material faults such as a pinhole or crack occur in the heat transfer tube wall. When such a leak occurs, it results an important phenomena, so called 'wastage' which may cause damage to or a failure of the adjacent tubes. Another type of phenomenon is a 'self-wastage' which is not wastage on a wall of the adjacent tubes, but which occurs on the inside of the leakage site itself. If a steam generator is operated for some time with this condition, it is possible to damage the leak hole itself, which may eventually enlarge into a much larger opening. There is a danger that the resultant leak rate caused by a self-wastage might create the state of a small leak, or even an intermediate leak which would then give rise to the problems of a multi-target wastage. It has been observed in this study and others that the diameter of the nozzle hole grows to become a larger size in a very short time. Therefore, it is very significant to predict these phenomena quantitatively from the view of designing a steam generator and its leak detection systems

[en] The supercritical CO₂ Brayton cycle system is known to be a promising power conversion system for improving the efficiency and preventing the sodium water reaction (SWR) of the current SFR concept using a Rankine steam cycle. PCHEs are known to have potential for reducing the volume occupied by the sodium-to-CO₂ exchangers as well as the heat exchanger mass relative to traditional shell-and-tube heat exchangers. Here, we report a study on a plugging test by the interaction of sodium and CO₂ to investigate design parameters of sodium channels in the realistic operating conditions. We investigated a plugging test by an interaction of sodium and CO₂ with different cross sectional areas of the sodium channels. It was found that the flow rate of sodium decreased earlier and faster with a narrower cross sectional area compared to a wider one. Our experimental results are expected to be used for determining the sodium channel areas of PCHEs

[en] In order to verify the concept of safety grade passive decay removal system PDRC (Passive Decay heat Removal Circuit) of KALIMER-600 and the design features to resolve the design issues for securing the cooling performance, the performance test is implemented. In this report, the preliminary test requirements for using as a guideline to the design of the experimental facility were established. Since the experimental facility should be designed so as to simulate the various thermal- hydraulic phenomena, as closely as possible, to be occurred in reference reactor during the decay heat removal operation, the design characteristics of the reference reactor (KALIMER-600) were analyzed for drawing major constitutive elements to be simulated in the facility. The preliminary test matrix was set up by the analysis of various design basis events and then the key test matrix was determined. Also, the priority for various thermal hydraulic phenomena which should be considered in the design of the experimental facility was determined by analyzing the phenomena for each key test matrix. Based on the analysis, the general design requirements for experimental facility were prepared and the design requirements for fluid systems and instrumentation were established. The test requirements in this report will be reflected in the scaling analysis and the basic design of the experimental facility. The test matrix specified in this report can be modified in the stage of main testing by considering the needs of experiments and circumstances at that time

[en] KAERI (Korea Atomic Energy Research Institute) will perform a test for a thermal hydraulic simulation with STELLA 1 for a Component Performance Test Sodium Loop in 2012, and subsequently will construct STELLA 2 for a Sodium Thermal hydraulic Experimental Facility in 2016. These facilities need to consist of a sensor for hydrogen concentration monitoring to control some of the impurities in a purification system in the future. In this paper, the senor manufactured by a shop at KAERI was introduced and tested

[en] A successful time for detecting a water/steam leak into sodium in the LMR SG (steam generator) at an early phase of a leak origin depends on the fast response and sensitivity of a leak detection system. It is considered, that the acoustic system is intended for a fast detecting of a water/steam into sodium leak of an intermediate flow rate, 1∼10 g/s. This intention of an acoustic system is stipulated by a key impossibility of a fast detecting of an intermediate leak by the present nominal systems on measuring the hydrogen in the sodium and in the cover gas concentration generated at a leak. During the self-wastage of a water/steam into sodium leak in a particular instant, it is usual in 30∼40 minutes from the moment of a leak origin, there is a modification of a leak flow out regime from bubble regime to the steam jet outflow. This evolution occurs as a jump function of the self-wastage of a leak and is escorted by an increase of a leak noise power and qualitative change of a leak noise spectrum. Subject of this study is by means of two experiments, one is an acoustic leak noise analysis of the water into sodium leak results in no damage to the LMR SG tube bundle, and another is for prediction of the frequency band under a high outflow leak condition. We experimented with the Argon gas injection considered with the phenomena of secondary leaks in real

[en] The use of sodium as a coolant in a liquid metal reactor(LMR) has many advantages due to its thermal properties while a disadvantage that a major sodium spill and a pipe rupture of sodium coolant systems will usually result in a sodium fire. The rise of temperature and pressure, the release of aerosol in the buildings as a result of a sodium fire must be considered for the safety measures of a LMR. Subsequent effect of a sodium fire depends upon whether the sodium continues to leak from the pipe or not, whether the ventilation system is running, whether the inert gas injection system is provided, whether the sodium on the floor is drained into the smothering tank or not, whether the building is sealed or not, etc. Therefore, for the safety of a LMR, it is necessary to understand the characteristics of a sodium fire, resulting from various types of leakage. ASSCOPS(Analysis of Simultaneous Sodium Combustion in Pool and Spray) is the computer code for the analysis of the thermal consequences of a sodium leak and fire in a LMFR that has been developed by JAEA in Japan. Computer code includes two sodium combustion codes called SOFIRE II and SPRAY. SOFIRE II code has been developed to compute 1-cell and 2-cell pool fire cases by Atomics International(AI), and the SPRAY code has been developed to evaluate the consequences of a postulated sodium spray release from LMFR piping leak by Hanford Engineering Development Laboratory(HEDL) in USA. This study describes a preliminary analysis of sodium leak and fire accidents in the S/G building of KALIMER. Various phenomena of interest are the spray and pool burning, peak pressure, temperature change, the drain system into the smothering tank, ventilation characteristics at each cell with the safety venting system and nitrogen injection system